perspiration
/ˌpɜ:spəˈreɪʃn; ˌpəspə`reʃən/ n[U]
(a) moisture given off by the body; sweat 汗; 汗水
drops of perspiration rolling down one's forehead 从额头上滚落的汗珠.
(b) process of giving off moisture through the skin 出汗; 流汗
Perspiration cools the skin in hot weather. 天热时出汗可使皮肤降温.